Degenerative myelopathy exon 1 (DM exon 1)
Degenerative myelopathy exon 1 (DM exon 1)
General description
Degenerative Myelopathy (DM) is a serious neurological disease in dogs that typically begins at around 8 years of age. The first signs include weakness and coordination problems in the hind legs. As the disease progresses, the front legs may also be affected, potentially leading to paralysis and paraplegia of all limbs. Incontinence may also occur. A variant in exon 2 of the SOD1 gene has been identified as a risk factor for the development of DM in many breeds. In Bernese Mountain Dogs, an additional variant in exon 1 of this gene has been identified, which is also associated with DM.
Breeds
Bernese Mountain Dog
Order details
| Test number | 8485 |
| Abbreviation | DM Exon 1 |
| Sample material | 0.5 ml EDTA blood, 2x cheek swab, 1x special swab (eNAT) |
| Test duration | 3-5 working days |
Test specifications
| Symptom complex | neuromuscular |
| Inheritance | autosomal recessive with age-dependent incomplete penetrance |
| Age of onset | from 8 years |
| Causality | High-risk factor |
| Gene | SOD1 |
| Mutation | A-T |
| Literature | OMIA:000263-9615 |
Detailed description
Canine degenerative myelopathy (DM) is a severe neurodegenerative disease with late onset at around 8 years of age. The disease is characterised by degeneration of the axons and myelin in the thoracic and lumbar regions of the spinal cord, causing progressive ataxia and paresis.
The first clinical signs are observed in the hind limbs as a sign of upper motor neuron dysfunction. Uncoordinated movement and weakness of the hind limbs, impaired proprioception and impaired reflexes develop. As the disease progresses, it spreads to the front limbs and manifests itself as flaccid paresis and paralysis, so that affected dogs lose the ability to walk 6 months to 2 years after the onset of symptoms. Late in progression of the disease, fecal and urinary incontinence can be observed. In affected small breeds, the disease often progresses more slowly than in affected large dog breeds.
Degenerative myelopathy was first described as a spinal cord disease, particularly in German shepherds. However, DM has been diagnosed in several other breeds, too. Because of the similarity of the symptoms, the differentiation between DM and other neuromuscular or skeletal diseases can be very difficult. A definitive diagnosis can only be made postmortem by the histopathological observation of neuronal degradation and demyelination of the spinal cord.
A genetic variant in exon 2 of the SOD1 gene (superoxide dismutase 1 gene) has been identified as a risk factor for the development of DM in many breeds.
In Bernese Mountain Dogs, there is also a genetic variant in exon 1 of this gene, which is also associated with DM in this breed. Both variants can be tested for in Bernese Mountain Dogs. The request can be made together or separately.
